I seem to have a loud popping in my transfer case, could this be something as simple as the chain is worn out and stretched out. I am a ford tech so im plenty capable of pulling it and rebuilding it. Although it seems it may be cheaper to just put a used one in it if its going to be more than just the chain. it seems to engage in all the gears fine, although does not seem to want to pull very hard in any of the. Secondly i found one for 80$ near me, are all the np242s the same my tag says 242 J.. the one im looking at says 242 ?J i cant tell if there is another marking before the J or if its just crap on the tag. Here is the link to the one im looking at buying http://atlanta.craigslist.org/nat/pts/2976712992.html will this work?
Thanks Austin

 

Figure about 200 for a rebuild kit with chain.. it does sound as though it's stretched.

What model and year is your rig? The transfercases have differing input gear spline counts and lengths you need to match accordingly.